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This artifact provides a single jar that contains all classes required to use remote Jakarta Enterprise Beans and Jakarta Messaging, including all dependencies. It is intended for use by those not using maven, maven users should just import the Jakarta Enterprise Beans and Jakarta Messaging BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

package io.netty.util;

import io.netty.util.internal.StringUtil;

import java.net.IDN;
import java.util.LinkedHashMap;
import java.util.Locale;
import java.util.Map;
import java.util.regex.Pattern;

/**
 * Maps a domain name to its associated value object.
 * 
 * DNS wildcard is supported as hostname, so you can use {@code *.netty.io} to match both {@code netty.io}
 * and {@code downloads.netty.io}.
 * 
 */
public class DomainNameMapping implements Mapping {

    private static final Pattern DNS_WILDCARD_PATTERN = Pattern.compile("^\\*\\..*");

    private final Map map;

    private final V defaultValue;

    /**
     * Creates a default, order-sensitive mapping. If your hostnames are in conflict, the mapping
     * will choose the one you add first.
     *
     * @param defaultValue the default value for {@link #map(String)} to return when nothing matches the input
     */
    public DomainNameMapping(V defaultValue) {
        this(4, defaultValue);
    }

    /**
     * Creates a default, order-sensitive mapping. If your hostnames are in conflict, the mapping
     * will choose the one you add first.
     *
     * @param initialCapacity initial capacity for the internal map
     * @param defaultValue the default value for {@link #map(String)} to return when nothing matches the input
     */
    public DomainNameMapping(int initialCapacity, V defaultValue) {
        if (defaultValue == null) {
            throw new NullPointerException("defaultValue");
        }
        map = new LinkedHashMap(initialCapacity);
        this.defaultValue = defaultValue;
    }

    /**
     * Adds a mapping that maps the specified (optionally wildcard) host name to the specified output value.
     * 
     * DNS wildcard is supported as hostname.
     * For example, you can use {@code *.netty.io} to match {@code netty.io} and {@code downloads.netty.io}.
     * 
     *
     * @param hostname the host name (optionally wildcard)
     * @param output the output value that will be returned by {@link #map(String)} when the specified host name
     *               matches the specified input host name
     */
    public DomainNameMapping add(String hostname, V output) {
        if (hostname == null) {
            throw new NullPointerException("input");
        }

        if (output == null) {
            throw new NullPointerException("output");
        }

        map.put(normalizeHostname(hostname), output);
        return this;
    }

    /**
     * Simple function to match DNS wildcard.
     */
    private static boolean matches(String hostNameTemplate, String hostName) {
        // note that inputs are converted and lowercased already
        if (DNS_WILDCARD_PATTERN.matcher(hostNameTemplate).matches()) {
            return hostNameTemplate.substring(2).equals(hostName) ||
                    hostName.endsWith(hostNameTemplate.substring(1));
        } else {
            return hostNameTemplate.equals(hostName);
        }
    }

    /**
     * IDNA ASCII conversion and case normalization
     */
    private static String normalizeHostname(String hostname) {
        if (needsNormalization(hostname)) {
            hostname = IDN.toASCII(hostname, IDN.ALLOW_UNASSIGNED);
        }
        return hostname.toLowerCase(Locale.US);
    }

    private static boolean needsNormalization(String hostname) {
        final int length = hostname.length();
        for (int i = 0; i < length; i ++) {
            int c = hostname.charAt(i);
            if (c > 0x7F) {
                return true;
            }
        }
        return false;
    }

    @Override
    public V map(String input) {
        if (input != null) {
            input = normalizeHostname(input);

            for (Map.Entry entry : map.entrySet()) {
                if (matches(entry.getKey(), input)) {
                    return entry.getValue();
                }
            }
        }

        return defaultValue;
    }

    @Override
    public String toString() {
        return StringUtil.simpleClassName(this) + "(default: " + defaultValue + ", map: " + map + ')';
    }
}